1. Field of the Invention
The invention proposes a method for producing a stator for a rotary electrical machine having a compact coil and having an optimized coefficient of filling of the recesses.
The invention proposes more particularly a method for producing a stator for a rotary electrical machine comprising an annular body in the internal cylindrical face of which there are produced axial recesses and comprising a plurality of phase windings consisting of conductors arranged in associated recesses in the body, of the type that comprises a step of depositing conductors on a linear support and two transfer steps.
The invention also concerns an arrangement of conductors on the linear support.
2. Description of the Prior Art
In this known method there are performed
a step of depositing conductors on a linear support with a principal longitudinal orientation, the top face of which comprises transverse recesses, comprising a first phase of depositing conductors in the recesses, so as to form a first layer of conductors,
a first step of transferring the conductors, from the linear support, onto an annular support with transverse principal axis whose external cylindrical face comprises transverse recesses distributed angularly about the transverse principal axis of the annular support, so that the two layers of conductors form two coaxial spirals on the annular support, and
a second step of transferring the conductors from the annular support onto the body of the stator.
It may be thought to produce the coil of the stator from two layers of superimposed conductors.
More precisely it may be thought to carry out a second phase of depositing conductors in the recesses, so as to form a second layer of conductors that is arranged vertically above the first layer.
This arrangement makes it possible to reduce the length of the linear support, which is determined according to the total number of recesses in the linear support.
Thus, by producing the windings by forming two layers of conductors on the linear support, the total length of the linear support is roughly divided by two compared with the length of the linear support on which the windings are formed only from a single layer of conductors.
According to this embodiment the two deposition phases of the method are independent of each other so that, for each winding on the stator, the step of depositing the conductors consists of consecutively depositing two distinct conductors on the linear support.
Each conductor is deposited on the linear support by means of a deposition head that describes, with respect to the linear support, a roughly sinusoidal movement from upstream to downstream during each deposition phase.
Each deposition phase therefore comprises a period of depositing the conductor, followed by a period of return of the deposition head during which the deposition head is not used. Such a method thus includes dead times that extend the total time taken for producing the stator.
In addition, the coil produced by such a method then comprises four coil supply lengths for each winding, each length forming one end of one of the two conductors, that is to say double compared with a coil produced from a single layer of conductors, which consequently increases the weight and complexity of the stator in particular.